This research project will study the therapeutic application of helium and heavy ions such as carbon, neon or argon, in the treatment of human cancers. This project is intended to test the potential advantages of improved dose distribution (helium) and increased biologic effect (neon, carbon). There will be continuation of refinement of fractionated, large field, spread out Bragg peak charged particle radiotherapy techniques as well as improvement in techniques for assessment of and compensation for tissue inhomogeneities in the particle beam path. Current pilot studies with helium ions will lead shortly to randomized clinical trials and we will soon institute Phase I - Phase II pilot studies with heavier ions such as carbon and neon at the BEVALAC.